Fluid-heater



W. A. AND J. A. DOBLE.

FLUID HEATER.

APPLICATION FILED MAR. 2, 1917 1,395,399. Patented Nov. 1, 1921.

WITNESSES.- INVENTOR. 3 an DOflLE 7? @Vm By M /7- 0085 F 1102 ATTORNEYSUNITED STATES PATENT OFFICE WILLIAM DOBLE AND JOHN A. DOBLE, OF SANFRANCISCO, CALIFORNIA, ASSIGNOBS TO DOBLE LABORATORIES, OF SANFRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

FLUID-HEATER.

- Specification of Letters Patent.

Patented Nov. 1, 1921.

To all whom it may concern:

Be it known that we, WILLIAM A. Donna and JOHN A. Donne, citizens of theUnited States, and residents of the city and county of San Francisco andState of California, have invented a certain new and usefulFluid-Heater, of which the following is a specification.

The invention relates to fluid heaters and particularlyto fluid heaterssuch as steam generators, water heaters and air heaters, employingliquid or gaseous fuel as the heating medium.

An object of the invention is to provide a fluid heater in which theactual combustion of the fuel occurs in thermal contact with theheat-absorbing medium. 7

Another object of the invention is to provide a steam generator which isparticularly applicable for use in automobiles, aeroplanes, submarinesand other vehicles.

Another object of the invention is to eliminate the fire box in a fluidheater burning liquid fuel.

The invention possesses other advantageous features, some of which, withthe fore going, will be set forth at length in the fol lowingdescription where we shall outline 11. full that form of the inventionwhich we have selected for illustration in the drawings accompanying andforming part of the following specification. In said drawings we haveshown one specific form of our generic invention and severalmodifications thereof, but it is to be understood that we do not limitourselves to such form, since the invention as expressed in thesucceeding claims may be embodied in a plurality of forms.

Referring to the drawings:

Figure 1 is a vertical section of one form of fluid heater of ourinvention, the fuel and air-feeding means being shown diagrammatically.

Fig. 2 is a cross section taken on the line 2-2 Fig. 1, the blower fanbeing omitted.

Fig. 3 is a section of a fragment of a modified form of heater.

In the drawings we have shown the invention embodied in a steamgenerator and shall so describe it in the specification, but it is to'be understood that the invention is not limited to steam generators.

The generator of our invention comprises a steam generating unit andmeans for producing a. flame in said unit so that the combustion of thefuel occurs within the steam generating unit. Heretofore, steamgenerators have been provided with fire boxes in which combustion of thefuel is substantially brick, which when the fire is first started,

absorb a large amount of heat retarding the initial generation of steam.Further, when the brick becomes hot, it gives oif its heat when the feedof fuel is reduced and thereby prevents an accurate control of the firedue to steam conditions within the boiler. In accordance with ourinvention, we eliminate the fire box and introduce the combustiblemixture directly into the device containing the heat-absorbing medium. a

The heat absorbing unit or steam genergit ing unit, as the case may be,consists in one embodiment of the invention, of a long tube 2 ofsufficient strength to withstand the pressure to which it is exposed.The diameter and length of the tube will be determined by the amount ofpower it is desired to enerate and by the conditions of instal ation. Inautomobile use it is evident that the length of the tube, if disposed ina straight line, should be less than the length of the vehicle.Surrounding the tube 2, preferably for its entire length, and spacedapart therefrom, is an outer tube or jacket 3, which is sealed at itsends to the inner tube 2, thereby forming a long, annular chambersurrounding the inner tube. This chamber is provided at its end adjacentthe outlet of 1 the inner'tube 2, with a water inlet pipe 4, through.which the feed water is forced in any desirable manner. At the end ofthechamber adjacent the inlet of the tube 2, is a 5. The-outer tube 3 steamdischar i g0 d d by a jacket 6 of heatis entirely surroun insulatingmaterial Means are provided for blowing a combustible mixture directlinto the inner tube. Connected to the end oi: the tube is a device forroducing and igniting a fuel spray and for blowing the resultant mixtureinto the tube wherem it is burned. This device may assume a plurality offorms and in the present embodiment comprises a casing including a fuelatomizing and ignition chamber? and an air-mixing chamber 8, which isconnected directly to the steam generator. The fuel atomizing chamber 7is provided with a liquid fuel nozzle, which in the present instancecomprises a shell 13 into which the nipple 14 is screwed, the nipplebeing provided with a fuel passage opening on the side therein withinthe shell and adjacent the end thereof. The nipple is narrowed adjacentits outer end to form an annular chamber within the shell, and a head onthe nipple forms, with the end of the shell, an annular nozzle, the areaof which is adjustable by screwing the nipple in the shell. Liquid fuelin measured quantity is fed under pressure from the supply tank 27 tothe liquid fuel nozzle by the measuring pump 28, which is preferably ofthe gear type. Surrounding the shell and spaced thereform whereby anannular chamber is formed, is a sleeve 15 which terminates in aninturned lip adjacent the end of the shell, and forms an annular nozzlesurrounding the fuel nozzle and in atomizing relation therewith. Airunder pressure is forced into the sleeve, whence it discharges, blowingthe fuel into a spray. The sprayproducing air is obtained from the highpressure blower 29. Arranged in the path of the fuel spray produced bythe air and fuel nozzles is an electric ignition device 18 comprisingtwo insulated electrodes connecting to the terminals of a transformer orinduction coil having a make-and-break device in the primary circuit. Aspark between the electrodes ignites the fuel spray. Su plementary airis supplied to the resu tant flame to form a combustible mixture at apoint in front of the ignition device, so that the spray is not diluteduntil after it is ignited. The supplementary air is supplied to themixing chamber 8 by the low pressure blower 20 which is preferablyarranged immediately adjacent the mixing chamber. In the presentconstruction we have shown the blower housing 21 secured directly to themixing chamber housing and the blower is arranged to blow air into themixing chamber in the direction of the steam enerator. Means areprovided for causing t e supple mentary air supplied by the blower tocontact with the flame on all sides without materially distorting theflame or blowing it toward one side of the mixing chamber.

chamber at the top and sides and forms a horseshoe shaped passage 23through which the air is blown into the mixing chamber. Thei ited sprayissues from under the hood and t e auxiliary air contacts with the flameon all sides, thereby producing complete combustion without materiallydistorting the flame. Means are provided for synchronously driving thelow pressure blower 20, the high pressure blower 29 and the fuel-meaauring pump 28, so that the speeds of these three devices alwayscorrespond and so that the relative'proportionaof fuel and air alwaysremain constant, and these proportions are originally adjusted toproduce a fuel mixture which burns with perfect combustion. In thpresent instance the two blowers and the fuel pump are driven by a motor31 which is furnished with current from a suitable source of supply,such as a storage battery 32. j

Means are provided for varying the speed of the blowers and pump inaccordance with variations in conditions of the heat-absorh' ing medium,in the present instance in accordance with variations-in steam pressurein the steam generator. Connected to the steam discharge ipe 5 is acylinder 38 having a spring-10a ed piston 34 therein, which is connectedto the rheostat arms 35. The rheostat 36 is in the motor circuit and isso arranged that a movement of the rheostat arm due to an increase insteam pressure in the boiler, produces a reduction in the speed of themotor, and vice versa. A switch 37 in the batter circuit serves to Startor stop the motor when desired. By this arrange ment, a perfectcombustible mixture is always produced, which is blown into and burnedin direct thermal contact with the heat-absorbing medium and the amountof mixture introduced in a given time is dependent upon conditions ofthe heat-absorbing medium.

The combustible mixture-producing device is preferably arrangedvertically and the main portion of the generating unit horizontally, theforward end thereof being turned upwardly to meet the mixture-producidevice. This arrangement is palticu arly adapted to automobiles, whereinthe'mixture producing device may bearranged under the hood and the steamgenerating unit may extend under the car in the direction of its length.For this use the tubes may be of small diameter, so that the gencratingunit will occupy a small space. By

turning the forward or hottest end of the generating unit upward, asteam chamber is provided within the unit.

In Fig. 3 we have shown a modified form of generator in which the innertube is formed of a longitudinally corrugated tube 25 which, on accountof its deep corrugations, presents an increased area to the flame and tothe heat-absorbing medium, therebv producing a generator of increasedcapacity in proportion to its length. The fluid spaces between thesuccessive corrugations are small, so that a small amount of fluid iscontained therein and the area of this small amount of fluid in contactwith the tube is great, so that the fluid is rapidly heated. Thecorrugations also serve to produce swirls and eddies of flame and hotgases within the tube, thereby retarding the discharge of the gasestherefrom. The cold fluid is introduced into the generator at thedischarge end of the tube and progresses toward the hot end, so that theflame and gases come successively in contact with colder surfaces,resulting in very eflicient thermal conditions. While we have describedthe combustible mixture producing device in connection with liquid fuel,it is to be understood that it may be used with gaseous fuel.

Subject matter disclosed, but not claimed, in this application, isclaimed in applicants co-pending application Serial No. 151,928, filedsimultaneously herewith, and it is understood that such subject matteris not disclaimed, abandoned or dedicated to the public.

We claim:

1. A fluid heater comprising a long tube, a jacket surrounding andspaced from said tube and forming with said tube a fluid containing andheating chamber, means for producing a fuel flame and directing it intoone end of said tube whereby the products of combustion pass throughsaid tube lon tudinally and discharge from the opposite end thereof, ahousing connecting the tube and said fuel flame producing means, a fluidinlet pipe connected to the chamber adjacent the as discharge end of thetube and a heated uid outlet pipe connected to the chamber at the flameinlet end of the tube.

2. A fluid heater, comprising a long horizontally disposed tube havingan upturned inlet endi a jacket surrounding and spaced from sai tube andforming therewith a fluid heating chamber, a fluid outlet connected tothe upturned portion of said chamber and means for producing a fuelflame in said tube.

3. A fluid heater, comprising a long tube having an upturned inlet end,a jacket surrounding and spaced from said tube and forming with saidtube a fluid heating chamher having an upturned end, a heated fluidoutlet pipe connected to the upturned end of said chamber, a cold fluidinlet pipe connected to the other end of said chamber, and means forintroducing a fuel flame downwardly into the upturned end of said tube.

4. The combination with means adapted to receive a heat-absorbingmedium, of means for measuring and feeding fuel and atomizing said fuel,means for feeding air to the atomized fuel and blowing the mixturedirectly into said heat-absorbing medium containing means wherein it isburned, and means for synchronously driving said fuel-measuring meansand said air-feeding means.

5. The combination with a steam generator, of a liquid fuel spraynozzle, a pump for forcing fuel through said nozzle, means for ignitingthe fuel spray, a blower for adding air to the i nited spray to producecomplete combustion and blow the ignited mixture into the steamgenerator wherein the mixture is burned, and mechanism responsive tochanges in steam pressure in the generator for simultaneously varyingthe speed of the pump and the blower.

6. The combination with means adapted to receive a heat-absorbingmedium, of a fuel-mixing device attached thereto, means for measuringand feeding the measured quantity of fuel to said device, means foratomizing said fuel, and means driven synchronously with saidfuel-measuring means for adding air to the atomized fuel and blowing themixture directly into said heat-absorblng medium containing meanswherein combustion of the mixture occurs.

In testimony whereof, we have hereunto set our hands at San Francisco,California, this 21st day of February, 1917.

WILLIAM A. DOBLE. JOHN A. DOBLE.

In presence of- T. H. MORGAN, V WILLIAI A. Dorm, Jr.

